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EP-4234342-B1 - AIR BAG DEVICE FOR PEDESTRIAN PROTECTION AND METHOD FOR PRODUCING SAME

EP4234342B1EP 4234342 B1EP4234342 B1EP 4234342B1EP-4234342-B1

Inventors

  • HANAWA AKIFUMI
  • ITO SATOSHI
  • TAMURA ATSUSHI

Dates

Publication Date
20260506
Application Date
20211012

Claims (6)

  1. A pedestrian protection airbag device (1,101) comprising: an inflator (20,120a,120b) that supplies expansion gas; and an airbag (10,110) that is expanded and deployed by the expansion gas for protecting a pedestrian who collides with a vehicle; wherein the airbag (10,110) includes a center chamber (12C,102C) extending in a width direction of the vehicle in the vicinity of a lower edge of a windshield (4), and side chambers (12R,12L) extending upward from both left and right end sections of the center chamber (12C,102C) at least along an A-pillar, and is configured such that gas supplied from the inflator (20,120a,120b) flows from the center chamber (12C,102C) to the side chamber (12R,12L), a folded section (16R,16L) is formed at which the side chamber (12R,12L) is folded back toward the center chamber (12C,102C) to be overlapped in a stowed state of the airbag (10,110), a pair of left and right partition panels (26R,26L) for partitioning the center chamber (12C,102C) and the side chambers (12R, 12L) are provided in the vicinity of the folded sections (16R, 16L), each of the pair of partition panels (26R,26L) is provided with a check valve in the vicinity of the folded sections (16R,16L) that prevents backflow of gas from the side chamber (12R,12L) to the center chamber (12C,102C) characterized in that end sections of the pair of left and right side chambers (12R,12L) overlap each other when the side chambers (12R,12L) are folded back at the folded section (16R,16L).
  2. The pedestrian protection airbag device (1,101) according to claim 1, wherein the inflator (20,120a,120b) is arranged and stowed in the vicinity of the center of the center chamber (12C,102C) in the left-right direction.
  3. The pedestrian protection airbag device (1,101) according to claim 1, wherein a plurality of the inflators (20,120a,120b) are provided, and the plurality of inflators (20,120a,120b) are arranged and stowed lined up in a line in the left-right direction inside the center chamber (12C,102C).
  4. The pedestrian protection airbag device (1,101) according to any one of claims 1 to 3, wherein the airbag (10,110) is configured such that a section corresponding to the center chamber (12C,102C) is formed into a roll shape, and then the side chambers (12R,12L) on both left and right sides are folded back toward the center side in the vicinity of the folded section (16R, 16L).
  5. The pedestrian protection airbag device (1,101) according to any one of claims 1 to 4, wherein the airbag (10,110) contains a lateral tether (22) that extends in the longitudinal direction of the center chamber (12C,102C) inside the airbag (10,110) and can restrict thickness of the airbag (10,110) during deployment and the pair of partition panels (26R,26L) are respectively arranged at left and right ends of the lateral tether (22).
  6. A method of manufacturing a pedestrian protection airbag device (1,101) according to one of the claims 1 to 5, comprising: a step of preparing an airbag (10,110) containing a center chamber (12C,102C) extending in a width direction of a vehicle near a lower edge of a windshield (4) and side chambers (12R,12L) extending upward from both left and right end sections of the center chamber (12C,102C) at least along an A-pillar, the airbag (10,110) being configured such that gas supplied from the inflator (20,120a,120b) flows from the center chamber (12C,102C) to the side chamber (12R, 12L); a step of setting a folded section (26R,26L) between the side chamber (12R,12L) and the center chamber (12C,102C) of the airbag (10,110); a step of providing a pair of left and right partition panels in the vicinity of the folded sections (16R,16L) for partitioning the center chamber and the side chambers; and a step of folding back and overlapping the side chamber toward the center chamber at the folded section (16R,16L), wherein a section of the airbag (10,110) corresponding to the center chamber (12C,102C) is formed into a roll shape, and then the side chambers (12R,12L) on the left and right sides are folded back toward the center side in the vicinity of the folded section (16R, 16L),wherein the pair of side chambers (12R,12L) are folded back so that end portions thereof overlap each other.

Description

TECHNICAL FIELD The present invention relates to a pedestrian protection airbag device for protecting a pedestrian or a cyclist who collides with a vehicle, and a method of manufacturing the same. BACKGROUND ART In order to protect occupants in the event of a vehicle collision, it is well known that vehicles are equipped with one or a plurality of airbags. These airbags include, for example, various forms such as: a so-called driver airbag which expands from near the center of the steering wheel of an automobile so as to protect a driver; a curtain airbag which deploys downward along an inner side of a window of the automobile so as to protect an occupant during a collision in a lateral direction of the vehicle, as well as when overturning and during a rollover accident; and a side airbag which is deployed between an occupant and a side panel so as to protect the occupant upon impact in the lateral direction of the vehicle. In addition, there is also a pedestrian protection airbag for protecting a pedestrian or a cyclist (a person riding a bicycle) who collides with a vehicle. A pedestrian protection airbag device includes a center chamber extending in a lateral direction (vehicle width direction) in the vicinity of a boundary between a hood and a windshield of a vehicle, and side chambers deployed upward from left and right end sections of the center chamber so as to cover an A-pillar. With an airbag device having such a structure, since the shape of the airbag is substantially U-shaped, the side chamber may oscillate (flutter) to the left and right when the airbag is deployed. In other words, the deployment behavior of the airbag is not stable, and rapid and sure protection of the pedestrian (or the cyclist) is difficult. Therefore, for example, a center chamber and side chambers connected by a strap has been proposed, as in Patent Document 1. However, there is risk that the strap may be caught on the neck of the pedestrian or cyclist during collision with the vehicle. Document US 2016 339 866 A1 discloses a pedestrian airbag device according to the preamble of claim 1. RELATED ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: Japanese Unexamined Patent Application 2006-219046 Patent Document 2: US 2026 339 866 A1 SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION In light of the foregoing, an object of the present invention is to provide a pedestrian protection airbag capable of safely stabilizing deployment behavior of the airbag, and a manufacturing method thereof. MEANS TO SOLVE THE PROBLEM In order to resolve the problem described above, the present invention is a pedestrian protection airbag device as defined by claim 1. Here, subjects to be protected by the present invention include not only "pedestrians" but also persons riding bicycles (cyclists). Further, the "windshield" may be referred to as a front glass. There is a description "the side chamber extends upward at least along an A-pillar;" however, in addition to the region covering the A-pillar, the side chamber and vicinity of the connecting section with the center chamber can include a section extending in the width direction of the vehicle. In the present invention, since the partition panel having the check valve is provided in the vicinity of the folded section between the center chamber and the side chamber, and the side chamber is folded toward the center chamber (center direction) in the vicinity of the folded section, when the airbag starts to deploy, the center chamber first expands and deploys in the front-to-back direction (longitudinal direction). At this time, the side chamber is maintained in a folded state. Thereafter, the expansion gas from the center chamber flows into the side chamber through the check valve of the partition panel, such that the folded section unfolds and the side chamber deploys. Gas flowing into the side chamber does not flow back toward the center chamber due to the effect of the check valve. As described above, in the present invention, a stable base is first established by the center chamber, and then the side chambers are deployed; therefore, the deployment behavior of the airbag (particularly, the side chambers) is stabilized. The inflator may be provided and stowed in the vicinity of the center in the left-right direction of the center chamber. Alternatively, a plurality of the inflators can be provided, and the plurality of inflators may be arranged and stowed inside the center chamber, aligned in the left-right direction. When the side chamber is folded back at the folded section, end sections of the pair of left and right side chambers overlap each other. The airbag can be configured such that after a section corresponding to the center chamber is formed into a roll shape, the side chambers on both left and right sides are folded toward the center side in the vicinity of the folded section. The airbag can be configured to include a lateral tether extending along a longitudinal directi